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Date: Tue, 19 Jan 2016 14:13:33 +0100
From: Peter Zijlstra <peterz@infradead.org>
To: Byungchul Park <byungchul.park@lge.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>,
        LKML <linux-kernel@vger.kernel.org>,
        Chris Metcalf <cmetcalf@ezchip.com>,
        Thomas Gleixner <tglx@linutronix.de>,
        Luiz Capitulino <lcapitulino@redhat.com>,
        Christoph Lameter <cl@linux.com>,
        "Paul E . McKenney" <paulmck@linux.vnet.ibm.com>,
        Mike Galbraith <efault@gmx.de>, Rik van Riel <riel@redhat.com>
Subject: Re: [PATCH 2/4] sched: Consolidate nohz CPU load update code
Message-ID: <20160119131333.GD6344@twins.programming.kicks-ass.net>
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 <20160114051840.GA4224@X58A-UD3R>
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On Thu, Jan 14, 2016 at 02:18:40PM +0900, Byungchul Park wrote:
> > +	__update_cpu_load_nohz(this_rq, READ_ONCE(jiffies), 0, 0);
> 
> This question is not directly related to this patch but I am just
> curious about... Should we use READ_ONCE on jiffies which is already
> volatile type?

I'd say so, if only because I forever forget that jiffies is declared
volatile and READ_ONCE() makes the intent explicit.